If a file system is created without specifying a data block size value, the data block size is calculated automatically on the basis of the file data area size or the maximum size of the partitions comprising the file system. The greater the file system size, the greater the data block size. The greater the data block size, the greater the maximum file size.
The table below shows the relationship between the file system size, the data block size and the maximum file size when a file system is created without the data block size being specified.
File system size | Data block size | Maximum file size |
|---|---|---|
to 1 TB | 8 KB | 1 TB - 8 KB |
( 1 TB + 1 Byte) to 2 TB | 8 KB to 16 KB | (1 TB - 8 KB) to (2 TB - 16 KB) |
( 2 TB + 1 Byte) to 4 TB | 8 KB to 32 KB | (1 TB - 8 KB) to (4 TB - 32 KB) |
( 4 TB + 1 Byte) to 8 TB | 8 KB to 64 KB | (1 TB - 8 KB) to (8 TB - 64 KB) |
( 8 TB + 1 Byte) to 16 TB | 16 KB to 128 KB | (2 TB - 16 KB) to (16 TB - 128 KB) |
( 16 TB + 1 Byte) to 32 TB | 32 KB to 256 KB | (4 TB - 32 KB) to (32 TB - 256 KB) |
( 32 TB + 1 Byte) to 64 TB | 64 KB to 512 KB | (8 TB - 64 KB) to (64 TB - 512 KB) |
( 64 TB + 1 Byte) to 128 TB | 128 KB to 1 MB | (16 TB - 128 KB) to (128 TB - 1 MB) |
(128 TB + 1 Byte) to 256 TB | 256 KB to 1 MB | (32 TB - 256 KB) to (128 TB - 1 MB) |
(256 TB + 1 Byte) to 512 TB | 512 KB to 1 MB | (64 TB - 512 KB) to (128 TB - 1 MB) |
(512 TB + 1 Byte) to 1PB | 1 MB | 128 TB - 1 MB |
( 1PB + 1 Byte) to 2PB | 2 MB | 256 TB - 2 MB |
Note
The file system size is not just the file data area size. It also includes the sizes of areas such as the metadata area and the update log area. Therefore, near the boundary values for file system sizes in the above table, the data block size values might be one step smaller.
See
Refer to "B.3 Limit Values" in the "Primesoft Distributed File System for Hadoop V1 User's Guide" for the file system maximum values.
The file system data block size can be changed during file system creation. Refer to pdfsmkfs under "Appendix A Command Reference" in the "Primesoft Distributed File System for Hadoop V1 User's Guide" for details.
